Remove `Environment::MAX_EVENT_TOPICS` and remove `Environment` generic type from event abstractions

[davidsemakula]

Maximum number of event topics is no longer configurable in pallet-revive (see https://github.com/paritytech/polkadot-sdk/blob/7ede4fd048f8a99e62ef31050aa2e167e99d54b9/substrate/frame/revive/src/limits.rs#L49)

NOTE: cargo-contract will also need to be update according (see #2580 (comment))